1. Field of the Invention
This invention relates to apparatus for sampling the contents of reactor vessels and has particular reference to apparatus suitable for removing a sample of catalyst from a catalytic reforming reactor while the reactor is in the normal operating condition.
2. Description of the Prior Art
Sampling devices of the general type described herein are known, and usually comprise a sampling chamber or cavity located within a reactor, which chamber or cavity can be operated from outside the reactor to selectively obtain a catalyst sample and deliver same to a sample receiver while the reactor is at normal operating conditions.
A catalyst sampler of the general type to which this invention pertains is described in U.S. Pat. No. 3,129,590. Another variation of this type of catalyst sampler is described in U.S. Pat. No. 3,561,274. The samplers described therein include provision for manually operating a rotatable shaft to selectively obtain a catalyst from within the reactor and to deliver the sample to a receiver, all while the reactor is at operating conditions of high temperature and pressure. Samplers as described in the aforementioned patents, and particularly in U.S. Pat. No. 3,561,274, have proven quite satisfactory in many respects, and have been widely utilized in commercial refineries. The catalyst sampler according to the present invention is in many respects similar to the one described in U.S. Pat. No. 3,561,274, but has advantages and features not found in the prior art devices as will be pointed out in detail below. Samplers as described in U.S. Pat. No. 3,561,274 are subject to the disadvantage that it is necessary to remove the sampler from the reactor in order to change the seals therein. This is generally undesirable as such reactors, even when not operating, are generally maintained under a positive nitrogen pressure to protect the catalyst content and to keep air out of the reactor. There has accordingly been a need for a catalyst sampler which could enable a catalyst sample to be removed from an operating reactor, and which could also allow for packing material to be replaced without the necessity of opening the reactor to the atmosphere. Such a catalyst sampler is provided by the present invention.